原帖由 Oops 於 2008-4-12 17:00 發表 
咩係 PMT ?
http://en.wikipedia.org/wiki/MPEG_transport_stream#PMT
PMT
Program Map Tables, or PMTs, contain information about programs. For each program, there is a PMT, with the PMT for each program appearing on its own PID. The PMTs describe which PIDs contain data relevant to the program. PMTs also provide metadata about the streams in their constituent PIDs. For example, if a program contains an MPEG-2 video stream, the PMT will list this PID, describe it as a video stream, and provide the type of video that it contains (in this case, MPEG-2). The PMT may also contain additional descriptors providing data about its constituent streams.
Also, it contains a “special” PMT (with the program_number (field in the PMT) equal to 0) which is the NIT PID on the TS. This “special PMT” is optional. But the NIT is not. So we can not find a NIT PID in the PAT, we MUST use the default value for the NIT PID. |